This is a national stage application of PCT/GB99/00632 filed Mar. 3, 1999.
The present invention relates to a method of cleaning the inside surface of a kitchen extraction duct or other grease duct which often become coated with a layer of grease, which is very difficult to remove.
Present duct cleaning systems involve blasting compressed air through the ducts and this has proven to be very effective in removing dry dirt such as dust. It does not, however, achieve good results when used to remove grease and similar deposits. This problem is presently overcome by manually scraping and scrubbing the ducts, where access is possible, but it is still difficult to ensure that the duct surfaces are cleaned thoroughly. Manual cleaning also requires considerable effort and is significantly restricted by the lack of accessibility to the ducts. A build-up of grease in extraction ducts is a serious fire risk and possible health risk, and should be avoided.
An object of the present invention is to provide a method of cleaning the inside surface of a kitchen extraction duct or other grease duct which enables grease to be removed from the inside surface thereof without the need for cutting-in and installing the large numbers of access doors required for manual cleaning.
The present invention provides a method of cleaning the inside surface of a kitchen extraction duct or other grease duct by application of solid carbon dioxide under pressure, to harden and dislodge material as described herein.